Cognitive Decline and AD-Genetic Risk: The Role of Physical Activity

Literature has suggested increased physical activity to be a key modifiable factor exhibiting a protective association with cognitive function and dementia. It has also been reported that increased physical activity engenders pronounced cognitive protection among APOE-epsilon 4 carriers when compared to non-carriers. Few studies have examined the same associations between midlife physical activity and later-life multi-domain cognition. Here we seek to explore midlife physical activity dependent attenuation of late-life multi-domain cognitive performance, and whether this association varies among APOE-epsilon 4 carriers versus non-carriers.
Methods
This study utilises baseline data from 987 cognitively healthy older adults aged 60-85, participating in the CHARIOT Prospective Readiness Cohort Main Study. Midlife physical activity data were collected through a self-reporting questionnaire. Cognitive performance was measured via a comprehensive range of validated neurocognitive assessments: MMSE, NART, Clinical Dementia Rating, RBANS, DKEFS, NAB Memory and Executive modules, CogState Brief Battery and Clinical Drug Research assessment system. Multivariate analyses will be applied to evaluate APOE-moderated associations between midlife physical activity and multi-domain late-life cognitive performance.
Results
Analyses of a sub-sample (N = 551, 54% F, mean age = 64) via multivariate analysis of variance (MANOVA) found a statistically significant difference between those with high versus low midlife physical activity on combined indices of cognitive performance (F = 2.48, p = .031). Sub-analysis of individual cognitive indices found significance for language (F = 7.97, p = .005), visuospatial (F = 8.13, p = .005) and RBANS global cognition (F = 8.74, p = .003). Mean scores indicated that later life language, visuospatial and global cognitive performance were significantly higher among subjects reporting higher midlife physical activity compared to those reporting low physical activity. Analyses will be extended to report associations between level of midlife physical activity and multi-domain cognitive performance in APOE-ɛ4 carriers versus non-carriers.
Conclusions
Findings indicate that higher levels of midlife physical activity may play a protective role in terms of later life domain-specific and global cognition. These outcomes will contribute towards innovative projects targeting dementia risk reduction strategies during midlife, specifically via promotion of regular physical activity.